A hot needle sinks when put on the surface of cold water. Will a cold needle float or sink in warm water?

sink

Explanation:

The Intermolecular force of attraction exists within the water molecule. This type of intermolecular force of attraction is known as a hydrogen bond. A hydrogen bond is a dipole-dipole intermolecular attraction that occurs when hydrogen is covalently bonded to highly electronegative elements of a small atomic size.

When the heat is applied to this intermolecular force, the heat disrupts the intermolecular force, and the surface tension is being broken. This is what caused a hot needle to sink when placed in cold water. But when a cold needle is placed on the surface of warm water, the cold needle will not break up the warm water's surface tension. As a result, the cold need sinks in the warm water.

explanation:

since this is put under health, i would define "ethical (medical) behavior" the way the oath for doctors is recited.   "first do no harm."

but the term in general means when given a choice between right and wrong, we should always choose right. if we do, then we are practicing ethical behavior.